Apparatus and method for driving plasma display panel to enhance display of gray scale and color

ABSTRACT

The present invention relates to an apparatus and method for driving a PDP (plasma display panel). An image signal processor of the apparatus performs gamma correction and error diffusion processes of input image signals. A quantization error compensator compensates quantization errors with respect to an automatic power control (APC) level of image data output from the image signal processor. An error diffuser sets part of the image data output from the quantization error compensator as display errors and diffuses the display errors to peripheral pixels. A memory control and address driver generates sub-field and address data corresponding to image data that have undergone error diffusion by the error diffuser, and applies the data to the PDP. An APC and sustain/scan pulse generator generates a sub-field arrangement structure according to the APC level, generates control signals based on the generated sub-field arrangement, and applies the control signals to the PDP.

CLAIM OF PRIORITY

This application makes reference to, incorporates the same herein, andclaims all benefits accruing under 35 U.S.C. § 119 from an applicationfor “APPARATUS AND METHOD FOR DRIVING PLASMA DISPLAY PANEL TO ENHANCEDISPLAY OF GRAY SCALE AND COLOR”, earlier filed in the KoreanIntellectual Property Office on Jul. 8, 2002 and there duly assignedSerial No. 2002-39319.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a plasma display panel. Moreparticularly, the present invention relates to an apparatus and methodfor driving a plasma display panel to enhance the display of gray scaleand color.

2. Description of the Related Art

A plasma display panel (PDP) is a display device in which a plurality ofdischarge cells are arranged in a matrix, and the discharge cells areselectively illuminated to restore image data, which are input aselectrical signals.

In such a PDP, a plurality of scan electrodes and sustain electrodes areformed with at least one pair opposing one another in parallel, and atleast one address electrode is formed at a predetermined distance fromthese electrodes and orthogonal to the same. A pulse voltage is appliedto at least one of the scan electrodes and the sustain electrodes, andan address voltage is applied to the address electrode. As a result,discharge occurs between the address electrodes and the scan electrodesand/or the sustain electrodes to thereby realize an address operationthat provides variations in electrical properties where these electrodesintersect. Also, a sustain operation is performed in which a sustainvoltage is applied between the scan electrodes and the sustainelectrodes following discharge such that discharge occurs only atlocations where variations in electrical properties arise between thescan electrodes and the sustain electrodes.

In such a PDP, the display of gray scale must be possible in order toexhibit the capabilities of a color display device. A method is used toachieve this, in which a single field is divided into a plurality ofsub-fields and the sub-fields are controlled by a process of timesharing.

The drive characteristics of PDPs are such that a high amount of poweris consumed during operation. Therefore, an automatic power control(APC) technique is used in which the amount of power consumed iscontrolled according to a load ratio (or an ASL (average signal level))of a displayed frame. That is, in the APC technique, the power consumedis limited to below a predetermined level while the number of sustainpulses is varied according to the load ratio of input image data.

With the use of the APC technique, the number of sustain pulsesoperating on each sub-field is varied according to the load ratio. Inparticular, depending on the load ratio, the number of total sustainpulses applied in 1 TV frame is varied such that each sub-field has anumber of sustain pulses corresponding to a gray scale display weightthat the sub-field has. Therefore, the number of sustain pulsesoperating on each sub-field also varies.

In the ideal case, in order to realize a linear relation between grayscale and the number of sustain pulses, the number of sustain pulsesmust be a real number. However, in practice, the number of sustainpulses must be an integer to realize such an outcome, in which case aquantization error results during generation of the number of sustainpulses.

For example, a number n_(ij) of sustain pulses of a jth APC level of anactual ith sub-field is obtained as shown in Equation 1 below.

$\begin{matrix}{n_{i\; j} = {\frac{w_{i}}{\sum\limits_{i = 1}^{N_{s\; f}}\; w_{i}}N_{TOTj}}} & \lbrack {{Equation}\mspace{14mu} 1} \rbrack\end{matrix}$

where W_(i) is a gray scale display weight of an ith sub-field, N_(sf)is a number of sub-fields, and N_(TOTj) is a total number of sustainpulses of a jth APC level.

The number n_(ij) of sustain pulses calculated using Equation 1 above iseither an integer or a real number, whereas the number of sustain pulsesused in practice is an integer. Therefore, during actual PDP driving,the number n_(ij) is rounded to the nearest whole number to obtain thenumber N_(ij). The quantization error resulting from such rounding isexpressed as δN_(ij). The corresponding relation is shown in Equation 2below.N _(ij)=Round(n _(ij))n _(ij) =N _(ij) +δN _(ij)  [Equation 2]

Accordingly, with respect to the jth APC level, a designated totalnumber of sustain pulses and a total number of sustain pulses actuallyobtained are not the same, and a difference between these amounts may beexpressed as a sum of the quantization errors as shown in Equation 3 asfollows.

$\begin{matrix}{{N_{TOTj} - {\sum\limits_{i = 1}^{N_{s\; f}}\; N_{i\; j}}} = {{\sum\limits_{i = 1}^{N_{s\; f}}{\delta\; N_{i\; j}}} \neq 0}} & \lbrack {{Equation}\mspace{14mu} 3} \rbrack\end{matrix}$

Quantization error rates with respect to each APC level are shown inFIG. 1. It is clear from the drawing that the larger the load ratio ofthe screen, the greater the spread in the quantization error rate duringload ratio variations.

The gray scale display weights of the sub-fields for the different loadrates become slightly distorted by the quantization errors. This causesa reduction in the ability to display gray scale such that gray scalecolors are distorted according to load ratio variations. As shown inFIGS. 2A and 2B, compared to before quantization, colors are distortedfollowing quantization when the APC levels are converted at the samegray levels when displaying low gray levels.

While driving the PDP, if gamma correction is performed, which isreverse correction of gray scale correction with respect to digitalimage data, gray scale in the displayed image that is low in brightnessis significantly lowered to thereby deteriorate picture quality. Toremedy this problem, Korean Laid-Open Patent No. 2002-14766 discloses atechnique in which error components of gray scale displayed following anincrease in gray scale during gamma correction are diffused to adjacentpixels. As an example, in the case where image data input for gammacorrection are 8 bits, data output through gamma correction areconverted to data of 12 bits. Subsequently, the lower 4 bits of the 12bits are separated by error diffusion and diffused to an adjacent pixelsuch that ultimately 8-bit data able to display low gray scale are inputto the PDP.

However, in such a conventional method, compensation with respect toquantization errors occurring when the APC technique is applied asdescribed above is not performed, and the errors caused by theinaccuracy in the number of sustain pulses are diffused to an adjacentpixel. As a result, a rate at which the consumed power varies accordingto the load ratio lacks uniformity.

SUMMARY OF THE INVENTION

It is therefore, an object to provide an apparatus and method fordriving a plasma display panel in which quantization errors generatedwhen an APC technique is applied are compensated, and the obtainederrors are diffused to adjacent pixels to thereby improve the display ofgray scale and color.

It is another object to provide a display device where the distortion ofsub-field weights according to load ratio occurring as a result ofquantization errors when an APC technique is applied is reduced suchthat gray scale display becomes more natural.

It is yet another object to provide a display device where by diffusingto adjacent pixels errors obtained through quantization errorcompensation, an improvement in the display of gray scale and colors isrealized.

In one embodiment, the present invention is an apparatus and method fordriving a plasma display panel in which quantization errors generatedwhen an APC technique is applied are compensated, and the obtainederrors are diffused to adjacent pixels to thereby improve the display ofgray scale and color.

In the apparatus for driving a plasma display panel, images of eachfield displayed on the plasma display panel corresponding to input imagesignals are divided into a plurality of sub-fields of differing weights,and weight values of these sub-fields are combined to display grayscale. The apparatus includes an image signal processor performing gammacorrection and error diffusion processes of the input image signals; aquantization error compensator compensating quantization errors withrespect to an automatic power control (APC) level of image data outputfrom the image signal processor, and outputting resulting image data; anerror diffuser setting part of the image data output from thequantization error compensator as display errors and diffusing thedisplay errors to peripheral pixels; a memory control and address drivergenerating sub-field data and address data corresponding to image datathat have undergone error diffusion by the error diffuser, and applyingthe sub-field data and the address data to the plasma display panel; andan APC and sustain/scan pulse generator that generates a sub-fieldarrangement structure according to the APC level of image data outputfrom the image signal processor, generates control signals based on thegenerated sub-field arrangement, and applies the control signals to theplasma display panel.

The quantization error compensator includes a frame buffer delaying thenoutputting the image data output from the image signal processor; an APClevel detector detecting a load ratio of the image data output from theimage signal processor, and calculating the APC level; a quantizationerror lookup table outputting a quantization error compensation amountwith respect to a number of sustain pulses for each gray scale by usingthe APC level calculated in the APC level detector; and an errorcompensator compensating the image data output from the frame buffer bya quantization error compensation amount output from the quantizationerror lookup table.

Further, the error compensator includes an expander expanding a width ofthe image data output from the frame buffer, and outputting resultingimage data; and a compensator compensating the image data expanded bythe expander by a quantization error compensation amount.

In the method for driving a plasma display panel, images of each fielddisplayed on the plasma display panel corresponding to input imagesignals are divided into a plurality of sub-fields of differing weights,and weight values of these sub-fields are combined to display grayscale. The method includes performing gamma correction and errordiffusion processes of the input image signals, and generatingcorresponding image data; compensating quantization errors according toan automatic power control (APC) level of the generated image data;performing an error diffusion process with respect to the image datahaving undergone quantization error compensation; and performing anaddressing operation of the plasma display panel according to the imagedata having undergone the error diffusion process.

Compensating quantization errors includes detecting a load ratio of thegenerated image data and calculating an APC level; obtaining aquantization error compensation amount with respect to a number ofsustain pulses for each gray scale, the quantization error compensationamount being obtained based on the calculated APC level; andcompensating the generated image data by the quantization errorcompensation amount.

Further, compensating the generated image data by the quantization errorcompensation amount includes enlarging a width of the generated imagedata; and compensating the enlarged image data by the quantization errorcompensation amount.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendantadvantages thereof, will be readily apparent as the same becomes betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings in which likereference symbols indicate the same or similar components, wherein:

FIG. 1 is a graph showing a quantization error rate according to APClevel;

FIGS. 2A and 2B are graphs showing a total number of sustain pulsesaccording to APC level respectively before and after quantization;

FIG. 3 is a block diagram of an apparatus for driving a plasma displaypanel according to an embodiment of the present invention;

FIG. 4 is a detailed block diagram of a quantization error compensatorof FIG. 3;

FIG. 5A is a graph showing an expansion relation of data input from anexpander of FIG. 4;

FIG. 5B is a graph showing a compensation relation of data input from acompensator of FIG. 4; and

FIG. 6 shows an example of a computer including a computer-readablemedium having computer-executable instructions for performing a methodof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described in detailwith reference to the accompanying drawings. It is to be understood thatthe structure of the present invention is useful not only for fieldemission displays, but also for similar flat panel displays.

FIG. 3 is a block diagram of an apparatus for driving a plasma displaypanel according to an embodiment of the present invention.

As shown in the drawing, an apparatus for driving a plasma display panel(PDP) includes an image signal processor 100, a gamma corrector 200, anormal scale error diffuser 300, a quantization error compensator 400, afine scale error diffuser 500, a memory controller 600, an addressdriver 700, an APC controller 800, and a sustain/scan pulse generator900.

The image signal processor 100 generates and outputs digital image datacorresponding to externally received image signals. The digital imagedata that are output are 8-bit data.

The gamma corrector 200 performs gamma correction (actually gammareverse correction) corresponding to reverse correction of gammacorrection to maintain compatibility with the illuminationcharacteristics of a cathode ray tube. The gamma corrector 200 performsgamma correction with respect to 8-bit image data output from the imagesignal processor 100, and outputs 12-bit data.

The normal scale error diffuser 0.300 applies display errors, which arediffused from peripheral pixels, with respect to the 12-bit data outputfrom the gamma corrector to thereby generate 8-bit image data. Since thenormal scale error diffuser 300 performs conventional error diffusionprocesses, a detailed description thereof will not be provided.

A quantization error compensator 400 receives the 8-bit image dataoutput from the normal scale error diffuser 300 and expands the data to12-bit data. The quantization error compensator 400 also performsquantization error compensation processes according to APC level withrespect to the expanded 12-bit data.

A fine scale error diffuser 500 applies display errors, which arediffused from peripheral pixels, with respect to the 12-bit data outputfrom the quantization error compensator 400 to thereby generate 8-bitimage data. Although the fine scale error diffuser 500 performs the sameerror diffusion process as the normal scale error diffuser 300, that is,the conventional error diffusion process, since the fine scale errordiffuser 500 performs an error diffusion process with respect to datathat has undergone quantization error compensation in the errorcompensator 400, a more minute error diffusion process is performed whencompared to the conventional process.

The memory controller 600 generates sub-field data corresponding to the8-bit image data output from the fine scale error diffuser 500 accordingto a control signal output by the sustain/scan pulse generator 900.

The address driver 700 generates address data corresponding to thesub-field data output from the memory controller 600, and applies theaddress data to address electrodes (A1, A2, . . . Am) of a plasmadisplay panel (PDP) 1000.

The APC controller 800 detects a load ratio using the 8-bit image dataoutput from the normal scale error diffuser 300, and calculates an APClevel according to the detected load ratio. The APC controller 800 alsocalculates a number of sustain pulses corresponding to the calculatedAPC level and an address pulse width of each sub-field.

The sustain/scan pulse generator 900 receives the number of sustainpulses and address pulse width of each sub-field from the APC controller800, and generates a corresponding sub-field arrangement structure, anda control signal for the operation of the memory controller 600. Thesustain/scan pulse generator 900 also generates sustain pulses and scanpulses based on the generated sub-field arrangement structure, andapplies these pulses respectively to sustain electrodes (X1, X2, . . .Xn) and scan electrodes (Y1, Y2, . . . Yn) of the PDP 1000.

FIG. 4 is a detailed block diagram of the quantization error compensator400 of FIG. 3.

With reference to the drawing, the quantization error compensator 400includes a frame buffer 410, an error compensator 420, an APC leveldetector 430, and a quantization error lookup table 440.

The frame buffer 410 delays the 8-bit image data output from the normalscale error diffuser 300 by one frame before outputting the data.

The APC level detector 430 detects the load ratio using the 8-bit imagedata output from the normal scale error diffuser 300, and calculates theAPC level according to the load ratio. The APC controller 800 may alsobe used for these operations since they are performed by the APCcontroller 800.

The quantization error lookup table 440 stores quantization errorcompensation amounts according to the number of sustain pulses dependingon gray scale based on APC level. The quantization error lookup table440 receives the APC level calculated in the APC level detector 430 andoutputs a quantization error compensation amount with respect to thenumber of sustain pulses of the corresponding gray scale. Thequantization error compensation amount with respect to the number ofsustain pulses depending on gray scale is determined from Equation 4below.

$\begin{matrix}{\frac{\sum\limits_{i = 1}^{N_{s\; f}}{\delta\; N_{i\; j}}}{N_{TOTj}} \cdot {\sum\limits_{i = 1}^{N_{s\; f}}\; w_{i}}} & \lbrack {{Equation}\mspace{14mu} 4} \rbrack\end{matrix}$

Referring to FIGS. 4 and 5A, the error compensator 420 includes anexpander 421 that expands the 8-bit image data Di output from the framebuffer 410 to 12-bit image data Dm. Referring to FIGS. 4 and 5B, theerror compensator 420 includes a compensator 422 that performscompensation of a quantization error amount output from the quantizationerror lookup table 440 with respect to 12-bit image data Dm output fromthe expander 421, and outputs 12-bit compensated image data Do to thefine scale error diffuser 500.

A method for driving a PDP that improves the display of gray scale andcolor according to an embodiment of the present invention will now bedescribed.

Image signals to be displayed on a screen by the PDP 1000 are convertedinto 8-bit digital image data by the image signal processor 100. Next,gamma correction corresponding to reverse correction of gamma correctionto maintain compatibility with CRT (cathode-ray tube) illuminationcharacteristics is performed by the gamma corrector 200 such that the8-bit digital image data are output to the normal scale error diffuser300 as 12-bit image data.

At the same time data of the lower 4 bits of the 12-bit image data inputto the normal scale error diffuser 300 are diffused to peripheral pixelsas display errors, the 12-bit image data are output as 8-bit image datafollowing the application of display errors diffused and received fromperipheral pixels to corresponding image data to perform normal scaleerror diffusion, and the 12-bit image data are output as 8-bit imagedata.

Next, the 8-bit image data output from the normal scale error diffuser300 is delayed by one frame in the frame buffer 410 of the quantizationerror compensator 400, input to the expander 421 of the errorcompensator 420, then enlarged as 12-bit image data as shown in FIG. 5Aand output.

The 8-bit image data output from the normal scale error diffuser 300 isinput also to the APC level detector 430 of the quantization errorcompensator 400 where the data is used to determine the APC level. TheAPC level determined in this manner is input to the quantization errorlookup table 440 to form the basis for determining the sustain pulsequantization error compensation amount according to gray scale.

The quantization error compensation amount determined in thequantization error lookup table 440 is input to the compensator 422 ofthe error compensator 420. The 12-bit image data enlarged by theexpander 421 are also input to the compensator 422.

The compensator 422 receives a quantization error compensation amountfrom the quantization error lookup table 440, and compensates andoutputs 12-bit image data expanded in and output from the expander 421.

Quantization errors are compensated by the error compensator 420 in thismanner. Also, at the same time data of the lower 4 bits of the 12-bitimage data input to the fine scale error diffuser 500 are diffused toperipheral pixels as display errors, the 12-bit image data are output as8-bit image data (following the application of display errors diffusedand received from peripheral pixels) to corresponding image data toperform normal scale error diffusion, and the 12-bit image data areoutput as 8-bit image data to the memory controller 600.

Accordingly, image data that have undergone quantization errorcompensation by the quantization error compensator 400 are errordiffused by the fine scale error diffuser 500 to thereby realize errordiffusion compensation with respect to quantization errors.

Subsequently, sub-field data are generated in the memory controller 600with respect to 8-bit image data output from the fine scale errordiffuser 500. Also, the address driver 700 generates address datacorresponding to sub-field data output from the memory controller 600and applies the data to the address electrodes (A1, A2, . . . Am) of thePDP 1000.

Using the 8-bit image data output from the normal scale error diffuser300, the APC controller 800 calculates the APC level, and determines andoutputs the number of sustain pulses corresponding to the calculated APClevel. The sustain/scan pulse generator 900 receives the number ofsustain pulses output from the APC controller 800 and generates acorresponding sub-field arrangement structure. The sustain/scan pulsegenerator 900 also generates sustain pulses and scan pulses based on theproduced sub-field arrangement, then applies the same respectively tothe sustain electrodes (X1, X2, . . . Xn) and the scan electrodes (Y1,Y2, . . . Yn) of the PDP 1000.

Address data are applied to the PDP 1000 from the address driver 700,and sustain pulses and scan pulses are applied to the PDP 1000 from thesustain/scan pulse generator 900 as described above. As a result, animage corresponding to the input image signals may be displayed on thePDP 1000.

The present invention can be also realized as computer-executableinstructions in computer-readable media. The computer-readable mediaincludes all possible kinds of media in which computer-readable data isstored or included or can include any type of data that can be read by acomputer or a processing unit. The computer-readable media include forexample and not limited to storing media, such as magnetic storing media(e.g., ROMs, floppy disks, hard disk, and the like), optical readingmedia (e.g., CD-ROMs (compact disc-read-only memory), DVDs (digitalversatile discs), re-writable versions of the optical discs, and thelike), hybrid magnetic optical disks, organic disks, system memory(read-only memory, random access memory), non-volatile memory such asflash memory or any other volatile or non-volatile memory, othersemiconductor media, electronic media, electromagnetic media, infrared,and other communication media such as carrier waves (e.g., transmissionvia the Internet or another computer). Communication media generallyembodies computer-readable instructions, data structures, programmodules or other data in a modulated signal such as the carrier waves orother transportable mechanism including any information delivery media.Computer-readable media such as communication media may include wirelessmedia such as radio frequency, infrared microwaves, and wired media suchas a wired network. Also, the computer-readable media can store andexecute computer-readable codes that are distributed in computersconnected via a network. The computer readable medium also includescooperating or interconnected computer readable media that are in theprocessing system or are distributed among multiple processing systemsthat may be local or remote to the processing system. The presentinvention can include the computer-readable medium having stored thereona data structure including a plurality of fields containing datarepresenting the techniques of the present invention.

An example of a computer, but not limited to this example of thecomputer, that can read computer readable media that includescomputer-executable instructions of the present invention is shown inFIG. 6. The computer 1100 includes a processor 1102 that controls thecomputer 1100. The processor 1102 uses the system memory 1104 and acomputer readable memory device 1106 that includes certain computerreadable recording media. A system bus connects the processor 1102 to anetwork interface 1108, modem 1112 or other interface that accommodatesa connection to another computer or network such as the Internet. Thesystem bus may also include an input and output interface 1110 thataccommodates connection to a variety of other devices.

In the apparatus and method for driving a plasma display panel of thepresent invention described above, the distortion of sub-field weightsaccording to load ratio occurring as a result of quantization errorswhen an APC technique is applied is reduced such that gray scale displaybecomes more natural. Further, by diffusing to adjacent pixels errorsobtained through quantization error compensation, an improvement in thedisplay of gray scale and colors is realized.

Although embodiments of the present invention have been described indetail hereinabove, it should be clearly understood that many variationsand/or modifications of the basic inventive concepts herein taught whichmay appear to those skilled in the present art will still fall withinthe spirit and scope of the present invention, as defined in theappended claims.

1. An apparatus for driving a plasma display panel in which images ofeach field displayed on the plasma display panel corresponding to inputimage signals are divided into a plurality of sub-fields of differingweights, and weight values of these sub-fields are combined to displaygray scale, the apparatus comprising: an image signal processorperforming gamma correction and error diffusion processes of the inputimage signals; a quantization error compensator compensatingquantization errors with respect to an automatic power control level ofimage data output from the image signal processor, and outputtingresulting image data; an error diffuser setting part of the image dataoutput from the quantization error compensator as display errors anddiffusing the display errors to peripheral pixels; a memory control andaddress driver generating sub-field data and address data correspondingto image data that have undergone error diffusion by the error diffuser,and applying the sub-field data and the address data to the plasmadisplay panel; and an automatic power control and sustain/scan pulsegenerator generating a sub-field arrangement structure according to theautomatic power control level of image data output from the image signalprocessor, generating control signals based on the generated sub-fieldarrangement, and applying the control signals to the plasma displaypanel.
 2. The apparatus of claim 1, wherein the quantization errorcompensator comprises: a frame buffer delaying the image data outputfrom the image signal process or by a frame and outputting the same; anautomatic power control level detector detecting a load ratio of theimage data output from the image signal processor, and calculating theautomatic power control level; a quantization error lookup tableoutputting a quantization error compensation amount with respect to anumber of sustain pulses for each gray scale by using the automaticpower control level calculated in the automatic power control leveldetector; and an error compensator compensating the image data outputfrom the frame buffer by a quantization error compensation amount outputfrom the quantization error lookup table.
 3. The apparatus of claim 2,wherein the error compensator comprises: an expander expanding a widthof the image data output from the frame buffer, and outputting resultingimage data; and a compensator compensating the image data expanded bythe expander by a quantization error compensation amount.
 4. Theapparatus of claim 2, wherein the quantization error compensation amountis calculated by the following expression:$\frac{\sum\limits_{i = 1}^{N_{s\; f}}{\delta\; N_{i\; j}}}{N_{TOTj}} \cdot {\sum\limits_{i = 1}^{N_{s\; f}}\; w_{i}}$where j is the automatic power control level of image data, W_(i) is aweight of an ith sub-field, N_(sf) is a number of sub-fields, N_(TOTj)is a total number of sustain pulses of a jth automatic power controllevel, and δN_(ij) is a quantization error of an ith sub-field in a jthautomatic power control level.
 5. The apparatus of claim 3, wherein8-bit image data are expanded into 12-bit image data by the expander. 6.The apparatus of claim 5, wherein the error expander performs diffusionof lower 4 bits of the 12-bit image data output from the expander asdisplay errors.
 7. The apparatus of claim 3, with the compensatorperforming compensation of a quantization error amount output from thequantization error lookup table with respect to image data output fromthe expander, and outputting compensated image data to the errordiffuser.
 8. The apparatus of claim 1, wherein the memory controllergenerates sub-field data corresponding to the image data output from theerror diffuser according to a control signal output by a sustain andscan pulse generator.
 9. The apparatus of claim 1, wherein thequantization error compensator comprises an error compensatorcompensating the image data output from a delayed image from the imagesignal processor by a quantization error compensation amount output froma quantization error lookup table.
 10. The apparatus of claim 9, whereinthe quantization error compensation amount is calculated by thefollowing expression:$\frac{\sum\limits_{i = 1}^{N_{s\; f}}{\delta\; N_{i\; j}}}{N_{TOTj}} \cdot {\sum\limits_{i = 1}^{N_{s\; f}}\; w_{i}}$where j is the automatic power control level of image data, W_(i) is aweight of an ith sub-field, N_(sf) is a number of sub-fields, N_(TOTj)is a total number of sustain pulses of a jth automatic power controllevel, and δN_(ij) is a quantization error of an ith sub-field in a jthautomatic power control level.
 11. The apparatus of claim 10, whereinthe error compensator comprises: an expander expanding a width of theimage data output from the frame buffer, and outputting resulting imagedata; and a compensator compensating the image data expanded by theexpander by a quantization error compensation amount.
 12. A method fordriving a plasma display panel in which images of each field displayedon the plasma display panel corresponding to input image signals aredivided into a plurality of sub-fields of differing weights, and weightvalues of these sub-fields are combined to display gray scale, themethod comprising: performing gamma correction and error diffusionprocesses of the input image signals, and generating corresponding imagedata; compensating quantization errors according to an automatic powercontrol level of the generated image data; performing an error diffusionprocess with respect to the image data having undergone quantizationerror compensation; and performing an addressing operation of the plasmadisplay panel according to the image data having undergone the errordiffusion process.
 13. The method of claim 12, wherein compensatingquantization errors comprises: detecting a load ratio of the generatedimage data and calculating an automatic power control level; obtaining aquantization error compensation amount with respect to a number ofsustain pulses for each gray scale, the quantization error compensationamount being obtained based on the calculated automatic power controllevel; and compensating the generated image data by the quantizationerror compensation amount.
 14. The method of claim 13, whereincompensating the generated image data by the quantization errorcompensation amount comprises: expanding a width of the generated imagedata; and compensating the enlarged image data by the quantization errorcompensation amount.
 15. A computer-readable medium havingcomputer-executable instructions for performing a method for driving aplasma display panel in which images of each field displayed on theplasma display panel corresponding to input image signals are dividedinto a plurality of sub-fields of differing weights, and weight valuesof these sub-fields are combined to display gray scale, comprising:performing gamma correction and error diffusion processes of the inputimage signals, and generating corresponding image data; compensatingquantization errors according to an automatic power control level of thegenerated image data; performing an error diffusion process with respectto the image data having undergone quantization error compensation; andperforming an addressing operation of the plasma display panel accordingto the image data having undergone the error diffusion process.
 16. Thecomputer-readable medium of claim 15, wherein compensating quantizationerrors comprises: detecting a load ratio of the generated image data andcalculating an automatic power control level; obtaining a quantizationerror compensation amount with respect to a number of sustain pulses foreach gray scale, the quantization error compensation amount beingobtained based on the calculated automatic power control level; andcompensating the generated image data by the quantization errorcompensation amount.
 17. The computer-readable medium of claim 16,wherein compensating the generated image data by the quantization errorcompensation amount comprises: expanding a width of the generated imagedata; and compensating the enlarged image data by the quantization errorcompensation amount.
 18. A computer-readable medium having storedthereon a data structure comprising: a first field containing datarepresenting performing gamma correction and error diffusion processesof the input image signals, and generating corresponding image data; asecond field containing data representing compensating quantizationerrors according to an automatic power control level of the generatedimage data; a third field containing data representing performing anerror diffusion process with respect to the image data having undergonequantization error compensation; and a fourth field containing datarepresenting performing an addressing operation of the plasma displaypanel according to the image data having undergone the error diffusionprocess.